The present invention relates to packaged animal poisons, particularly packaged poison/bait mixes which can be fixed in place. It appears to be especially well suited for providing a packaged rodenticide/bait to control rodents.
There are a variety of existing poison baits which attract murine (e.g. rodents such as mice and rats) or other animals (e.g. crawling insects such as cockroaches, ants, crickets and earwigs) for the purpose of killing them. For example, relatively large solid rodenticide blocks have been developed in which the poison and bait are combined with a paraffin wax. These blocks are positioned for use without any surrounding packaging. See e.g. U.S. Pat. Nos. 4,891,218 and 5,044,113.
Such baits often contain much more poison and bait than are needed to attract and kill a single rodent. Because of the time delay between feeding and death, the animal may eat much more of the bait than is needed to kill it. This wastes material.
Further, a consumer or a business will not typically want to disclose to visitors or customers that they have a rodent infestation. The larger the bait/rodenticide, the harder it will be to hide it.
Another type of known bait is a package of small poison bait pellets. For example, “place packs” are rodent chewable packages, made for example of polyglysine-lined paper, containing such pellets. Such place packs are initially left unopened when placed in a desired location. The bait attracts rodents, notwithstanding the closed package. Rodents will be baited to gnaw through the package to reach the rodenticidal bait.
“Sachet” packages are boxes or packets of such pellets. These are opened by the consumer before leaving the pellets for the rodents. They commonly use cardboard or plastic sheeting for their packaging material, but the material is not important as the rodents do not need to chew through the packaging to access the bait.
Once the first rodent has gnawed through the package, or the package has been opened by the consumer, pellets may be spilled out of the package (e.g. due to contact by rodents or a human). Aside from the fact that this is visually messy, there is a potential hazard regarding leaving small pieces of poisonous material strewn around a floor. Moreover, cleaning up the scattered pellets can expose consumers or others to the poison if the bait isn't carefully handled.
U.S. Pat. No. 4,514,960 teaches using microwave energy to mold a wax-based insecticide/insect bait block within a dispensing package. This helps reduce the spilling potential of the insecticide. However, no structure is depicted for using this technology.
U.S. Pat. No. 5,720,951 teaches that rodenticidal baits can have included therein a food substance of interest to the rodent (e.g. wheat or sugar), a poison (e.g. brodifacoum, which is a coumarin anticoagulant, warfarin, or bromadiolone), a binder such as wax, and a human aversion agent, such as denatonium benzoate, which is a bittering agent sold under the trade name Bitrex®. A low concentration of Bitrex® will not interfere with rodent feeding, but will be so bitter as to cause a small child who might try to eat the bait to spit it out immediately.
Nevertheless, there still is a need for developing improved packaged animal poisons, particularly with respect to the placement of small, confined “servings” of bait at desired feeding locations, and with respect to providing means for assuring consumers regarding the amount of bait remaining.